The International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) Moving Picture Experts Group (MPEG) and the Telecommunication Standardization Sector of the International Telecommunications Union (ITU-T) Video Coding Experts Group (VCEG) organized a Joint Collaborative Team on Video Coding (JCT-VC) in 2010, and started to develop next-generation video standard technology, known as High Efficiency Video Coding (HEVC), and then completed the development of this technology in January 2013. HEVC enables compression efficiency to be improved by about 50% compared to H.264/AVC High Profile, which was previously known to exhibit the highest compression performance among existing video compression standards.
Meanwhile, three-dimensional (3D) video vividly provides a user with a stereoscopic experience as if he or she were viewing and sensing the real world, through a 3D stereoscopic display device. As research related to this technology, the development of 3D video standards is continually progressed by the Joint Collaborative Team on 3D Video Coding Extension Development (JCT-3V), which is the joint standardization group of ISO/IEC MPEG and VCEG. 3D video standards include both an advanced data format, which may support the playback, etc. not only of stereoscopic video but also of auto-stereoscopic video, using actual video and depth information maps thereof, and technology standards related to the advanced data format.
Further, 3D-HEVC, the standardization of which is under development as a 3D extension of HEVC, may use a motion merge process as a prediction encoding tool. The motion merge process is a method for inheriting motion information, derived from neighboring blocks of the current block, without change, and utilizing the inherited motion information as information about the motion of the current block. The motion merge process in 3D-HEVC is based on HEVC.
Further, 3D-HEVC may use an inter-view motion merge process based on images at multiple views. That is, in 3D-HEVC, motion information may be derived from a block at the position corresponding to that of the current block (hereinafter referred to as a ‘reference block’) among blocks in neighboring views.
However, 3D-HEVC is problematic in that when motion is uniform, information about the motion of the current block cannot be derived from the reference block, and thus an inter-view motion merge process cannot be used.
Meanwhile, Korean Patent Application Publication No. 10-2013-7027419 (entitled “Method and Apparatus of Motion and Disparity Vector Prediction and Compensation for 3D Video Coding”) discloses a method for obtaining a motion vector (MV)/motion vector predictor (MVP) or a disparity vector (DV)/disparity vector predictor (DVP) associated with a skip mode, a merge mode or an inter mode for the block of the current picture in 3D video coding.